Continuous progress of large scale integration (LSI) circuits, based on nano-scale complementary-metal-oxide-semiconductor technologies, has carried developing information technologies.
Recently, however, it is difficult to suppress power consumption in LSI circuits, increasing with expansion of performance requirements for the circuits on large-scale information processing. In particular, power loss, caused by electric charge flow through wiring in the circuits, is a critical issue for further development of LSI technology. Therefore it is desired to realize the way, being available in the circuits, by which one can transmit signals indicating information without electric current.
Spin waves are the propagating disturbances of magnetization in magnetic materials, and can transfer information, being expressed such as magnetization directions, from a point to another in the materials. The information transmission using spin waves is not accompanied with electric current. Recent research achievements in the field of spintronics allow to the generation of spin waves in magnetic thin films using nano-size elements on the films. The spin-wave-devices can be built, which utilize the physical features of spin waves such as superposition to carry out information processing, by monolithic integration of generators, modulators, and detectors for spin waves onto the films.